The major objective of this project is to study hyperthermia alone or combined with radiation as a potential therapeutic modality, and concurrently, evaluate and improve temperature measurement as a diagnostic aid to cancer detection. The diagnostic aims are to determine whether breast temperatures integrated over a period of days can detect early malignancies and whether a different approach to thermography can increase diagnostic capabilities. Project studies: 1) Develop methods for localized heating of tumors, including low frequency RF current fields. Establish techniques for thermal dosimetry and temperature control for therapy. Construct temperature sensing devices for incorporation into brassieres and for temperature difference integration. Incorporate new developments in infrared detection into thermography to improve its diagnostic capabilities. 2) Evaluation of the effects of heat on tissue culture systems, especially in terms of heat-radiation synergism and oxygen enhancement ratios as a function of temperature and time-dose factors. 3) Evaluation of the effects of heat alone and heat with radiation on normal tissue tolerances and experimental tumors in small animals. Physiologic studies of the effects of whole body hyperthermia on mammals and mammalian organ systems. 4) Therapy trials on large animals with spontaneous tumors to obtain information on normal tissue damage, treatment planning, and tumor control. 5) Phase I clinical trials will be started the latter portion of this grant to evaluate the clinical potential of hyperthermia as a therapeutic agent.